The present invention relates to dispensing cartons for sheet materials such as polymeric sheets, metallic foils, and other sheet materials, particularly those suitable for use in the containment and protection of various items including perishable materials. The present invention further relates to such cartons which permit end-loading of the roll of product into the carton during the manufacturing process.
Sheet-like materials for use in the containment and protection of various items, as well as the preservation of perishable materials such as food items, are well known in the art. Such materials can be utilized to wrap items individually and/or can be utilized to form a closure for a semi-enclosed container.
One class of such materials in common use today comprises those of various compositions formed into a thin, substantially two-dimensional, conformable web commonly supplied in rolled form. Common examples of such materials are polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyethylene (PE), polypropylene (PP), aluminum foil, coated (waxed, etc.) and uncoated paper, and the like. Another recently-developed class of materials for similar applications comprises a three-dimensional, conformable web comprising an active substance such as adhesive on at least one surface protected from external contact by the three-dimensional surface topography of the base material.
With such materials, it is commonplace to provide a carton for containing and dispensing these sheet materials. Cartons of conventional design are typically fashioned from a paperboard material which is cut and folded to form a box-like construction when edges and flaps are secured to one another. The sheet material is frequently wound upon a plastic or paperboard tube to form a cored roll. A wide variety of carton materials and sheet material/roll configurations may be suitable for various applications.
In order to provide an aesthetically pleasing and easy to grasp carton shape, particularly for larger diameter rolls of product, it would be desirable to provide at least one side of the carton with reduced corner protrusion, such as a hexagonal or octagonal shape, which more closely approximates a curved surface and therefore more closely approximates the curved shape of a consumer""s hand when grasping the carton. At the same time, however, a symmetrically-shaped hexagonal or octagonal carton is more prone to rolling over due to its more nearly circular cross-section. Accordingly, it would be desirable to retain some of the stability characteristics provided by a square or rectangular carton which has a high degree of corner protrusion to resist rolling over.
Most asymmetrically shaped cartons such as a semi-hexagon (with half of the cross-section being hexagonal and half being rectangular) are incompatible with end-loaded cartoners and require the use of a top-loader design. More specifically, end-loaded cartoners rely upon the ability of the carton blank to be folded upon itself and glued along a glue seam to form a flattened tubular/cylindrical structure which can then be erected to its desired final cross-section, the roll of product inserted from one end, and the end flaps glued shut. If a carton cannot be assembled into such a flattened and then erected tubular structure due to the geometry of the side surfaces, the carton must be assembled in such as way as to permit loading the roll of product through one of the sides (typically the xe2x80x9ctopxe2x80x9d) prior to final assembly rather than being inserted through one end. Top loaders are typically slower in operation than end loaders, leading to reduced output and are typically less reliable.
Most cartons in the prior art lack any feature for permitting the consumer to rotate the roll of product from the exterior of the carton to either rotate the roll to expose the end of the web of material or to rotate the roll to wind up excess sheet material and draw the end of the web back toward or into the carton. Many cartons rely upon the weight of the product roll itself to maintain it in its orientation within the carton, and the roll may move about within the carton during use.
Typical cartons in the prior art also utilize interlocking flaps or other devices to hold the carton lid in a closed condition between uses. However, such devices are often comparatively fragile in service and/or difficult to manufacture, and consequently some cartons omit such locking features entirely.
Accordingly, it would be desirable to provide an asymmetrical carton which is compatible with end-loading cartoners.
It would further be desirable to provide such a carton having additional features to facilitate location of the end of the roll of product and a releasable lid locking device.
It would also be desirable to provide such a carton which may be readily and economically manufactured and utilized for containing and dispensing sheet materials.
The present invention provides an asymmetrical carton for containing and dispensing a roll of sheet material. The carton has a longitudinal axis, and has both an erected condition and a flattened condition. The carton when erected forms a cylindrical structure having an asymmetrical polygonal cross-section formed from a plurality of substantially planar side panels. The carton has fold lines defined by the intersection of adjacent side panels, and is foldable into a flattened condition by folding the carton at two fold lines to form a substantially planar structure.